Effect of Intrapersonal and Interpersonal Behavior Change Strategies on Physical Activity Among Older Adults

Key Points Question Can combining intrapersonal and/or interpersonal behavior change strategies (BCSs) with physical activity (PA) interventions promote sustained increases in total PA among community-dwelling older adults who are insufficiently active? Findings In this randomized clinical trial of 309 community-based adults 70 years or older, those who received a PA intervention with interpersonal BCSs exhibited greater increases in their total PA for up to 12 months after the intervention than those who received a PA intervention without interpersonal BCSs. Conversely, participants who received PA interventions with intrapersonal BCSs exhibited no significant differences in PA than those who did not receive intrapersonal BCSs. Meaning Interpersonal BCSs such as peer-to-peer experience sharing and learning should be considered in efforts and interventions that promote the sustained uptake of PA among older adults.


Introduction
2][3] To counteract these problems, safe and effective 4 aerobic, muscle-strengthening, and balance activities are recommended for all older adults, 3 yet less than 16% meet minimum recommendations. 5One reason for the poor uptake of PA is limited knowledge regarding which types of behavior change strategies (BCSs) effectively promote sustained increases in PA in older adults. 3,6,7The current study presents results from a community-based randomized intervention factorial trial (Community-Based Intervention Effects on Older Adults' Physical Activity), Ready Steady (RS) 3.0, that tested the relative effects of 2 types of BCSs, intrapersonal and interpersonal, on community-dwelling older adults' PA.
[20] Systematic reviews suggest both types of BCSs are associated with PA. 8,9,[18][19][20][21][22] However, experimental evidence regarding their main effects and interactions on total PA is lacking, 3,7,21 except for a prior preliminary study (RS 2.0) that showed that interpersonal BCSs, but not intrapersonal BCSs, integrated into a PA intervention elicited increased PA after the intervention for up to 6 months. 23e present study, RS 3.0, used a randomized factorial design to address the gap in the literature and replicated the earlier RS 2.0 study 23 but with a larger sample and a longer follow-up. 24 tested the main and interaction effects of intrapersonal and/or interpersonal BCSs integrated into an intervention comprising an evidence-based PA protocol and a wearable PA monitor (PAM) on older adults' PA.

Study Design
The RS 3.0 trial was designed as a 2 × 2 full factorial randomized clinical trial.The factorial design and analyses enabled testing intrapersonal and interpersonal BCS components' main and interaction effects when combined with the Otago Exercise Program 25 and a wearable PAM.The exercise program consists of 17 strength and balance exercises and a walking program that are learned and individually tailored, with instruction to perform 3 times per week at home or location of choice. 26e approach was efficient because each effect estimate involved all 4 conditions. 27The trial design, protocol, and rationale are shown in Supplement 1 and a prior publication. 24

Participants
Community-dwelling older adults were recruited using newspaper advertisements, online sources, printed flyers, presentations at community events, and word of mouth and were enrolled in 13 waves.Entrance criteria were being 70 years or older, not meeting the national guidelines recommended by the Physical Activity Guidelines for Americans Advisory Committee 3 of at least 1 type of PA (eg, strength, balance, or aerobic), the ability to walk with or without an aid, 1 or more selfreported fall risks, 28 having no lower-extremity injury or surgery within the last 6 weeks, and having no self-reported neurocognitive disorder or a score of less than 4 on the cognitive impairment screening tool with 6 items developed by Callahan and colleagues, 29 in which scores range from 0 to 6, with higher scores (ie, 4 to 6) indicating a lower likelihood of cognitive impairment.The Exercise Assessment and Screening for You was also administered to ensure safety. 30Those who responded yes to questions about cardiovascular symptoms, frequent falls, or untreated dizziness obtained clearance from their primary care practitioner.We collected self-reported data on sex, race, and ethnicity to characterize populations for generalizability of findings.Self-reported race and ethnicity categories included Black or African American; Hispanic, Latino, or Spanish; White; and other race (Asian Indian, Chinese, Filipino, Indigenous, or some other race or ethnicity).Each participant received a wearable PAM (fitness tracker) and compensation of $70 for each assessment (up to $280 total).

Study Procedure Baseline Period
The baseline period included 3 contacts.During the first 2 contacts, participants completed baseline health and demographic questionnaires and received a new, wearable PAM. 31,32During the third baseline contact, participants completed self-reported questionnaires, and their accelerometer data from the previous 7 days were collected from wearable PAMs.They also received advanced, in-depth orientation and instructions for using the PAM.1).A total of 38 pairs of partners or friends eligible for the study and who requested to receive the intervention in the same small group were randomized together to minimize contamination between study conditions. 33To conceal random allocation sequences until interventions were assigned, the study analyst (Q.W.) generated 1 allocation sequence for each wave of 16 to 24 participants using SAS, version 9.4 (SAS Institute Inc) and provided access to the study manager after the study manager communicated that the wave was enrolled and completed baseline assessments.The study manager then assigned participants to assessments were masked to condition assignments and intervention content through the use of numeric codes for condition labels, the key to which they did not have access.

Intervention
Condition and meeting-specific curricula, manuals, and workbooks were created to guide interventionists and participants through the small-group intervention.The intrapersonal and interpersonal BCSs were considered experimental intervention components in conditions 1, 2, and 3.
Information about popular health and age topics was provided as attention control content in condition 4, which contained no BCS.The evidence-based OEP 25,34 and wearable PAMs 3,35 were considered core components, integral to interventions in all conditions.In-depth details about each component's delivery and behavior change content, links to behavior change techniques, 36 their dosages, and what participants were encouraged to do with each BCS were previously reported. 37perimental Components | In general, the interventionist delivered each BCS by first introducing it and then facilitating its practice during 2 intervention meetings.The meetings involved encouragement to build on, test, and implement it at home between intervention meetings and after intervention completion. 37e intrapersonal BCS experimental component consisted of 5 BCSs that incorporated personal reflection on PA-related experiences, beliefs, desires, and routines.These BCSs (highlighted in the Box) were selected based on theoretical and empirical evidence 19,38,39 and targeted the putative psychosocial mechanisms of readiness, self-efficacy, and self-regulation.
The interpersonal BCS experimental component consisted of 5 BCSs that incorporated peer-topeer sharing and learning about PA-related motivations, experiences, and knowledge.These BCSs (highlighted in the Box) were selected based on theoretical and empirical evidence 14,15,38 and targeted the putative psychosocial mechanisms of readiness, self-efficacy, self-regulation, and social support.
The condition that contained no intrapersonal or interpersonal BCS included educational attention control content.Participants received information about and discussed 1 health topic for 20 minutes at each meeting: safety during PA, falls, pain, nutritional supplements, sleep, hearing, memory, and vaccinations. 40re Components | The exercise program, adapted for small groups, 41,42 included the gradual introduction, demonstration, individualization, practice, and progression of 5 leg-strengthening and 12 balance-challenging exercises, plus encouragement to walk daily at one's usual pace (Supplement 1).It also included instruction and encouragement to perform the PAs learned and practiced during intervention meetings at home or at a preferred location at least 2 or 3 times per week after the intervention.
Wearable PAMs were provided to each participant, with displays consistent with the selfmonitoring feature of the exercise program and PA promotion guidelines. 29,30Support for learning about and using the device was provided throughout the study. 24,43

Outcomes and Measures
5][46] Total PA was measured by self-report using the PA Scale for the Elderly as a secondary source of data if adherence to wearing the PAM was low. 47,48Post hoc outcomes included additional objective indicators of PA averaged over 7 to 10 days: total PA operationalized as daily step count and moderate and vigorously intense PAs (MVPAs; aerobic movement fast and strenuous enough to burn off 3 to 6 times as much energy per minute than when sitting quietly and vigorous aerobic movement fast and strenuous enough to burn off Ն6 times as much energy per minute than when sitting quietly) operationalized as minutes of both combined. 49tcomes were assessed at baseline and at 3 time points after the intervention: 1 week, 6 months, and 12 months.Research staff connected deidentified fitness tracker accounts for each participant to Fitabase (Small Steps Labs LLC), a wearable research data management platform that includes the validation of participant wear time and data through minute-level heart rate and intensity data. 50The staff instructed participants to wear the PAM on their nondominant wrist during waking hours for at least 7 days, synchronize it frequently, and charge it at least every 5 days.At baseline and in cases during postintervention assessments when participants did not have internet access or a fitness tracker-compatible phone, wearable PAMs were synchronized by research staff to a study touchscreen tablet personal computer.
Staff collected data from 7 to 10 days before assessment meetings to overlap with the administration of the PA Scale for the Elderly.They checked accelerometer data against the minimum validation criteria of 4 or more days, including a weekend; 10 or more hours per day of wear time; and nonwear time of 60 or more minutes of continuous 0 measurements of heart rate or intensity data.If minimum validation criteria were not met, participants were asked to continue wearing the PAM, and a follow-up assessment was scheduled.Except for participants who withdrew from the study (Figure 1), data from all participants met valid wear-time criteria across all time points with less than 1% at the minimum level of valid wear-time criteria.

Sample Size
A target sample size of 308 was determined based on an expected 15% attrition, 80% power under a 2-tailed hypothesis test, and a significance level of P = .05to detect main or interaction effects of intrapersonal and interpersonal BCS intervention components of at least 0.2 (Cohen d). 19,51Although small, this effect size is considered clinically meaningful in older people and translates to 10 to 13 additional minutes of PA per day, or 670 to 870 additional steps per day. 19

Statistical Analysis
All participants' data were included in the study and analyzed according to their randomly assigned conditions.Analysis of covariance models were used to assess changes in each outcome at each postintervention time point, controlling for baseline values.The 2-level factors in models were receipt of the experimental components intrapersonal (conditions 1 and 3 vs conditions 2 and 4) or interpersonal (conditions 2 and 3 vs conditions 1 and 4).These factors were effect coded with 2 levels indicating exposure (yes, +1; no, −1). 27Separate multivariable models were run with interaction terms for intrapersonal and interpersonal factors for each postintervention assessment time point.The statistical significance of all tests was set at a 2-sided level of P = .05.All statistical calculations and analyses were performed using SAS, version 9.4 (SAS Institute Inc).
To assess potential clustering effects of partnered participants and intervention small-group membership, we extended analysis of covariance models with the outcome of mean (SE) daily total minutes of PA to include random variable terms for each.Cluster analysis results were congruent with analyses without the random-effects terms and presented in the eFigure and eTable 3 in Supplement 2.

Enrollment and Participant Characteristics and Intervention Attendance
A total of 309 participants were enrolled in the study (Figure 1), of whom 305 (98.7%) completed the intervention, and 302 (97.7%) had complete data.Table 1  Abbreviation: MVPA, moderate and vigorously intense physical activity (PA; aerobic movement fast and strenuous enough to burn off 3 to 6 times as much energy per minute than when sitting quietly and vigorous aerobic movement fast and strenuous enough to burn off Ն6 times as much energy per minute than when sitting quietly).
a All intervention conditions included the Otago Exercise Program and a wearable PA monitor as core intervention components.
b Other race includes Asian Indian, Chinese, Filipino, Indigenous, or some other race.d Based on the Brief Pain Inventory-Short Form, a 9-item, self-report questionnaire used to evaluate the average intensity and impact of a person's pain; scores range from 0 to 10, with higher scores indicating greater pain severity. 52Based on the Patient-Reported Outcomes Measurement Information System scale, version 1.1, Global Health, which is composed of standardized scores based on the US adult population, including older adults, with mean (SD) scores of 50 (10) and scores greater than 50 representing greater self-ratings of physical or mental health.53 f Chronic conditions were self-reported.
g Participants meeting each type of PA recommended in the PA guidelines as reported during screening. 3No enrollees reported meeting more than the minimum recommendations for more than 1 type of recommended PA: aerobic, strength training, and balance-challenging movements.
h Mean (SD) daily minutes of total PA, daily step count, and daily minutes of MVPA were measured via triaxial accelerometers in wearable activity monitors, in which the algorithm to classify each minute as being in sedentary, light, moderate, or vigorous aerobic activity for each minute is proprietary.
i Based on the self-reported PA Scale for the Elderly, in which scores range from 0 to more than 400, with higher scores indicating greater PA.Abbreviation: MVPA, moderate and vigorously intense physical activity (PA; aerobic movement fast and strenuous enough to burn off 3 to 6 times as much energy per minute than when sitting quietly and vigorous aerobic movement fast and strenuous enough to burn off Ն6 times as much energy per minute than when sitting quietly).

Primary Outcomes
a All intervention conditions included the Otago Exercise Program and a wearable physical activity monitor as core intervention components.
b Measured using an accelerometer within participants' commercially available, wearable PA monitor.All daily unadjusted means were an estimated time point, based on 7 to 10 days of data.
c Measured using the self-reported PA Scale for the Elderly, in which scores range from 0 to more than 400, with higher scores indicating greater PA. 47 After adjustment for baseline minutes of PA, participants who received the intervention The interaction effect of receiving interpersonal and intrapersonal components, adjusting for the other, on PA was not statistically significant at any postintervention time point (eTable 1 in Supplement 2).Self-reported PA did not differ significantly by receipt of the intervention components with intrapersonal BCSs (no vs yes) or with interpersonal BCSs (no vs yes) nor was there a significant interaction between these components at any postintervention time point (eTable 1 in Supplement 2).Analyses indicated that receipt of the intrapersonal component had no significant effect on mean (SE) daily step counts or mean (SE) daily minutes of MVPA.There were not any significant interaction effects of receiving intrapersonal and interpersonal components, adjusting for the other, on these metrics at any postintervention time point (eTable 1 in Supplement 2).

Discussion
To our knowledge, the RS 3.0 randomized clinical trial is one of the first studies to test the distinct and combined effects of more than 1 type of BCS 6 within a PA intervention on older adults' total PA up to 12 months after an intervention. 21In a sample of community-dwelling older adults with low baseline PA, interventions that included interpersonal BCSs led to significant initial and sustained increases in objectively measured total PA and MVPA.
While this finding is generally consistent with prior research on PA interventions for older adults, it advanced this literature by specifically identifying interpersonal BCSs within PA interventions as helpful in promoting sustained PA in older adults. 54Overall, the magnitude of the effect of PA interventions with interpersonal BCSs on participants' total PA and MVPA was clinically meaningful 55 and exceeded short-term outcome effectiveness benchmarks recently published. 56The findings also replicated a prior study, RS 2.0, by some of us, 23 in a larger sample and longer follow-up.Other intervention studies with interpersonal BCSs plus intrapersonal BCSs have also shown increases in PA of older adults, 57 African American adult women, 58 and adolescents. 59However, more specific evidence about the unique effects of intrapersonally vs interpersonally oriented BCSs is sparse and inconclusive. 8,9,14It is possible that the peer-to-peer sharing and learning, 13 undergirding discussions about interpersonal BCSs in RS 3.0, supported the development of social capital 18 (eg, visiting with neighbors, attending organized group meetings, and networks) and social integration (eg, involvement with peripheral social ties). 60idence generated by RS 3.0 regarding the importance of integrating interpersonal BCSs into PA interventions for older adults is promising and has implications for future research.2][63] Examining the feasibility and benefit of integrating the intervention component of RS 3.0 comprising interpersonal BCSs into existing programs that promote the uptake and maintenance of PA among older adults (eg, Active Living Every Day, Walk With Ease) 64 is also warranted.[67] The observation that using intrapersonal BCSs did not distinctly elicit increases in PA in older adults would appear to contradict the general conclusions drawn in some literature reviews that interventions with individual-level cognitive and behavioral strategies are associated with greater increases in PA. 19,54 However, more specific findings from some reviews indicate that certain BCSs, such as goal setting and action planning, are not associated with increased PA.In contrast, others are, such as coping planning. 8,9Given that most studies included in these reviews have evaluated intrapersonal BCSs bundled together with all intervention content (eg, interpersonal BCSs) and delivery components, it is difficult to discern which BCSs and components contributed to positive effects and which did not. 8,15,19Future research is needed to identify whether there are specific intrapersonal BCSs that are worth including in PA interventions for older adults. 3ndings of no significant intervention effects on self-reported PA measured are consistent with past research that shows that intervention effects are greater among studies using objective measures than those using self-report measures. 49Well-known biases associated with self-report measures of PA, 68 as well as patterns of inconsistencies shown in prior research (eg, those with very low PA self-report more activity than measured using an accelerometer), 69 could have contributed to these findings.1][72] Thus, future research should use objective measures when possible to estimate PA quantity and use self-report measures for other reasons, such as to explore perceived compared with actual PA and the types, domains, and contexts of one's PA. 49,70

Limitations
This study has limitations.Wearable PAMs, included as a core intervention component, may not be widely accessible.Although several baseline characteristics of the sample in our study represent older adults in Minneapolis and Saint Paul, the study sample was not large enough to examine intervention effects in subgroups of participants (eg, varied levels of baseline PA, disabilities, or chronic conditions). 65A well-known limitation of total PA minutes, step count, and MVPA metrics is that they may not fully capture all PA types recommended in the guidelines (eg, balance challenging and leg strengthening) or some aerobic PAs (eg, bicycling and swimming). 3Finally, conducting the study during the COVID-19 pandemic may have influenced PA for participants in dynamically varied ways.However, the number of participants enrolled before or after the start of the COVID-19 pandemic was similar across all 4 conditions (Table 1).

Conclusions
In this randomized clinical trial among community-dwelling older adults with low levels of PA, an 8-week intervention comprising an evidence-based PA protocol, a PAM, and interpersonal BCSs involving peer-to-peer learning and sharing, but not intrapersonal BCSs, resulted in significant increases in total PA and MVPA, which were sustained for up to 12 month after the intervention.
Future research should examine approaches to disseminating and implementing the RS intervention and its interpersonal BCS component within existing community-based programs and services.
Conducted in upper Midwest urban community centers in Minneapolis and Saint Paul, Minnesota, the study enrolled participants between November 17, 2017, and June 15, 2021, and all assessments were completed by September 2, 2022.Intervention delivery was paused between March 2020 and May 2021 due to the COVID-19 pandemic, but individual postintervention assessments continued using infectionprevention precautions.The University of Minnesota's Institutional Review Board approved the study protocol, and participants provided written and verbal informed consent.This study followed the Consolidated Standards of Reporting Trials (CONSORT) reporting guideline for randomized controlled trials.

Figure 1 .
Figure 1.Diagram of Participant Flow

c
Participation in Ready Steady 3.0 was, at least in part, during the first phase of the COVID-19 pandemic, between March 2020 and May 2021.

Figure 2 .
Figure 2. Effect of Intrapersonal and Interpersonal Behavior Change Strategies (BCSs) on Older Adults' Total Physical Activity (PA) 40 24

Randomization
Participants were randomized to interventions with the following components: intrapersonal BCS, the exercise program, and PAM; interpersonal BCS, the exercise program, and PAM; intrapersonal and interpersonal BCS, the exercise program, and PAM; or attention control information, the exercise program, and PAM.All interventions included 8 weekly small-group meetings with discussion,

JAMA Network Open | Geriatrics Effect
of Intrapersonal and Interpersonal Behavior Change Strategies on Physical Activity

Table 2
summarizes unadjusted means (SD) for all outcomes.Figure2shows differences in the mean (SE) changes in daily minutes of total PA averaged over 7 to 10 days, measured using wearable PAMs at baseline and at each postintervention assessment.

Table 2 .
Primary and Ad Hoc Outcomes by Condition 24fect of Intrapersonal and Interpersonal Behavior Change Strategies on Physical ActivityDownloaded from jamanetwork.combyguest on 03/10/2024 will focus on secondary and exploratory outcomes measured in this study, including fall rates, quality of life, and putative physical and psychosocial mechanisms.24 Future publications JAMA Network Open | Geriatrics JAMA Network Open.2024;7(2):e240298.doi:10.1001/jamanetworkopen.2024.0298(Reprinted) February 29, 2024 10/16 Longitudinal Analysis of Effects of Interpersonal Behavior Change Strategies on Primary Outcome of Average Daily Minutes of Total Physical Activity eTable 3. Potential Clustering Effects eReferences eFigure.